Castel del Monte, built by Holy Roman Emperor Frederick II. Anyone for Pentagons?

Of all the buildings and monuments built by F2H, the jewel is, without doubt, the Castel del Monte,

18 km from Andria in Bari, Apulia, it sits on a hill 540m high, dominating the surrounding country. Described by some as the finest castle in Europe, the Castel del Monte was built as a garrison to protect the territory of Capitanata, know known as Puglia, though probably used mainly as a hunting residence (those falcons again!). Some claim it was designed as the largest astronomical observatory of the Middle Ages. Whatever the case, its most striking feature is its octagonal symmetry, with eight massive octagonal towers laid out around an octagonal central courtyard. It is a masterpiece of building precision, by someone who liked the number 8.

Castel del Monte, built 1229-1249

In 1997, UNESCO decided that Castel del Monte "is of outstanding universal value in its formal perfection and its harmonious blending of cultural elements from northern Europe, the Muslim world, and classical antiquity. Castel del Monte is a unique masterpiece of medieval military architecture, reflecting the humanism of its founder, Frederick II Hohenstaufen."

OK, no one knows to what extent Frederick worked on the designs himself, but his interest in mathematics stares out for all to see, and its layout demonstrates its designer's deep knowledge of astronomy. This is a castle that could not have been built by anyone in Europe at the time other than Frederick II.

Nearest airport (regular flights from Rome), and lots of good hotels: Bari